Most of the time, the reason you see pusher fans are for lack of space in front of the motor.It's not to say pusher fans don't work because I had a pusher fan on my pro street car and it worked fine.
If you have the room to mount a puller, then by all means do it. I do suggest getting a Spal fan. They have the least amonut of static pressure drop when attached to the radiator. You also want to have a fan that will span the core of the radiator .